Why is KMnO4 Purple in Colour

Answer: In KMnO4, Mn is in +7 oxidation state and have all the 3d-orbitals vacant. Mn7+ ion is surrounded tetrahedrally by four oxide ions. All oxide ions have filled 2p-orbitals. There is transfer of an electron from filled 2p-orbitals of oxide ion to vacant d-orbitals of Mn7+ ion. Since p-orbitals are ungerade and d-orbitals are gerade, therefore, electron transition from p-orbitals of O2- to d-orbitals of Mn7+ ion is Laporte allowed i.e., ΔL = ±1 and also there is no change in spin multiplicity during electronic transition. Therefore, transfer of an electron is Laporte and Spin allowed. Therefore, KMnO4 is intensely purple in colour.

Related Questions

Why is Ti(H2O)6) 3+ violet in colour ?

What is the difference between dd transition and charge transfer transition ?

What is the reason for the colour of potassium dichromate ?

How Mn2+(aq) ion gives light pink colour ?

💾 Recommended Articles